1. Field of the Invention
The present invention relates to soft lithium-titanium-zinc ferrites having a resistivity of at least 10.sup.7 ohm-cm measured at 20.degree. C. and 100 volts, which are particularly well-suited to use in the manufacture of magnetic deflectors, especially deflection yokes for television receivers.
2. Description of the Prior Art
The ferrites of the present invention are particularly useful in the manufacture of electronic components for use in low-frequency applications. Materials currently in use for this kind of application are primarily manganese-zinc ferrites and magnesium-zinc ferrites. Each of these has disadvantages which render them less than ideal with respect to the combination of properties which are desirable in such applications.
Manganese-zinc ferrites can be produced at low cost and have high initial permeabilities, but their resistivities are low, on the order of 1,000 ohm-cm. As a consequence, they must be electrically insulated when used in the manufacture of magnetic coils, and this substantially increases the total cost price of devices in which they are used.
Nickel-zinc ferrites may attain a resistivity as high as 10.sup.5 ohm-cm, but their cost is prohibitive and their magneto-striction is large, which generates background hum in television receivers.
Magnesium-zinc ferrites having minor substitution of manganese and copper are capable of resistivities of 10.sup.6 ohm-cm, but they cannot be manufactured below a temperature of 1250.degree. C.
A need therefore, continues to exist for a ferrite having high resistivity, high initial permeability, high saturation induction and high Curie point, and which can be manufactured at relatively low cost and at relatively low temperatures.